JP5321911B2 - Valve timing control device - Google Patents

Description

  The present invention relates to a valve opening / closing timing control device that adjusts the opening / closing timing of an intake valve and an exhaust valve of an internal combustion engine used in an automobile, and more specifically, a drive-side rotating body that rotates synchronously with a crankshaft, and a drive A driven-side rotating body that is coaxially disposed with respect to the side-rotating body and that rotates synchronously with a camshaft for opening and closing the valve of the internal combustion engine, a fluid pressure chamber formed by the driving-side rotating body and the driven-side rotating body, A partition provided in at least one of the driving side rotating body and the driven side rotating body to partition the fluid pressure chamber into a retarding chamber and an advance chamber, and a fluid capable of controlling the supply and discharge of the working fluid to and from the fluid pressure chamber A valve opening / closing timing control device comprising: a control mechanism; and a lock mechanism capable of constraining a relative rotation phase of the driven-side rotator with respect to the driving-side rotator to a predetermined phase between a most retarded angle phase and a most advanced angle phase. About.

  Conventionally, as described in Patent Document 1, a driving side rotating body (in the literature, “shoe housing”), a driven side rotating body (in the literature, “vane rotor”), a driving side rotating body and a driven side rotating body, A fluid pressure chamber (referred to as “accommodating chamber” in the literature), and a partition portion (“vane” in the literature) provided on the driven-side rotating body so as to partition the fluid pressure chamber into a retarded angle chamber and an advanced angle chamber. , A fluid control mechanism (in the literature, “oil pump”, “switching valve”, “drain”) that can control the supply and discharge of the working fluid to and from the fluid pressure chamber, and the relative rotational phase of the driven side rotating body with respect to the driving side rotating body There is a valve opening / closing timing control device provided with a lock mechanism (“restraining means” in the literature) that can restrain the angle to a predetermined phase between the most retarded angle phase and the most advanced angle phase.

  With the invention described in Patent Document 1, it is possible to reliably set the relative rotation phase to the optimum initial phase when starting the engine based on the operation of the lock mechanism. Therefore, it is possible to optimize the intake timing and ignition timing of the engine to obtain a low emission engine with less harmful combustion exhaust, for example, hydrocarbon (HC).

  Normally, during engine operation, the displacement force in the retard direction and the advance direction based on the torque fluctuation of the camshaft acts on the driven-side rotating body. This displacement force, on average, works in the retarding direction, and the driven-side rotator tends to be displaced in the retarding direction. Hereinafter, the displacement force obtained by averaging the displacement force in the retard direction and the advance direction based on the torque variation of the camshaft is referred to as “an average displacement force in the retard direction based on the torque variation of the camshaft”. The valve opening / closing timing control device described in Patent Document 1 includes an advance means for applying torque in the advance direction to the driven-side rotating body, whereby an average displacement force in the retard direction based on torque fluctuations of the camshaft. Regardless of this, the relative rotational phase can be smoothly and rapidly displaced in the advance direction.

JP 2000-345816 A

  In recent years, there has been a demand for improvement in fuel consumption of internal combustion engines in order to deal with environmental problems, etc., the working fluid supply pump has been reduced in size and volume, and the supply pressure of the working fluid to the fluid pressure chamber has decreased. ing. As a result, the development of a valve opening / closing timing control device capable of obtaining an appropriate operating state even when the supply pressure is low is a problem. In particular, during idling operation, the rotational speed of the internal combustion engine is low, and the supply pressure of the working fluid is considerably low. Further, at this time, the fluid temperature of the working fluid is high, the viscosity is low, and the fluid pressure is hardly transmitted. For this reason, the driven-side rotating body tends to flutter in the retarding direction and the advancement direction due to the displacement force in the retarding direction and the advancement direction based on the torque fluctuation.

  In the valve opening / closing timing control device on the intake side, the relative rotation phase is often set to a phase near the most retarded angle phase during low-speed rotation such as during idling operation. Therefore, when the pump is downsized and reduced in capacity in the valve opening / closing timing control device described in Patent Document 1, the supply pressure of the working fluid is considerably low during idling operation, and the retarding direction based on the torque fluctuation of the camshaft is reduced. Since the advance angle means is provided so as to cancel out the average displacement force, it is difficult to stably keep the driven side rotating body at a phase near the most retarded angle phase. Therefore, the driven-side rotator may flutter and a stable idling operation may not be obtained. Moreover, there is a possibility that abnormal noise may be generated due to the fluttering of the partition.

  In order to solve this problem, for example, it is conceivable to increase the pressure receiving area of the partition receiving the fluid pressure as a whole by enlarging the fluid pressure chamber and the partition, or increasing the number of fluid pressure chambers. . However, this increases the size of the valve opening / closing timing control device, which contradicts the above technical problem.

  An object of the present invention is to provide a valve opening / closing timing control device that enables low emission at the start of an internal combustion engine and enables stable idling operation even when the supply pressure of the working fluid is low. .

A first characteristic configuration of the valve timing control apparatus according to the present invention is a drive-side rotator that rotates synchronously with a crankshaft of an internal combustion engine, and is arranged coaxially with the drive-side rotator. A driven-side rotator that rotates in synchronization with a camshaft for opening and closing the valve, a fluid pressure chamber formed by the drive-side rotator and the driven-side rotator, and the fluid pressure chamber as a retard chamber and an advance chamber A partition provided on at least one of the drive side rotor and the driven side rotor, a fluid supply / discharge mechanism capable of controlling supply / discharge of the working fluid to / from the fluid pressure chamber, and the drive side rotation A lock mechanism capable of constraining a relative rotational phase of the driven-side rotator relative to a body to a predetermined phase between a most retarded angle phase and a most advanced angle phase, and displacing the relative rotated phase toward the most retarded angle phase. The drive side rotor and the driven side rotor A biasing mechanism for exerting constantly biasing force Te equipped with, the strength of the biasing force, the rotational speed of the internal combustion engine is applied from the side of the retard chamber at a predetermined rotational speed in the partition portion The sum of the displacement force composed of the fluid pressure of the working fluid and the biasing force acts on the driven-side rotating body based on torque fluctuations of the camshaft when the rotation speed of the internal combustion engine is the predetermined rotation speed. The urging force is larger than the displacement force in the advance direction of the displacement force, and the biasing force is based on the torque fluctuation of the camshaft when the rotation speed of the internal combustion engine is the predetermined rotation speed. This is the point set so that the displacement force acting on the rotating body is less than the displacement force in the advance direction .
There is in point.

  With this configuration, the driven-side rotator has an average displacement in the retarded direction based on the urging force of the urging mechanism and the torque fluctuation of the camshaft as a force that relatively rotates the driven-side rotator in the retarded direction. Forces always work. Therefore, even if the internal combustion engine is appropriately started with the relative rotational phase being constrained to a predetermined phase by the lock mechanism and then the idling operation is performed and the fluid pressure received by the partition portion decreases, the above-described biasing force and the above-described cam The relative rotational phase can be stabilized at the most retarded phase or a phase near the most retarded phase by the average displacement force in the retarded direction based on the torque fluctuation of the shaft. As a result, the idling operation can be stabilized even if, for example, the pump capacity is reduced in the fluid supply / discharge mechanism.

  With this configuration, when the rotation speed of the internal combustion engine is a predetermined rotation speed, for example, at low speed rotation, such as during idling, the working fluid for maintaining the relative rotation phase at a phase near the most retarded angle phase. Even when the supply pressure is low, the displacement force in the advance direction out of the displacement force based on the torque fluctuation of the camshaft is canceled out by the urging force in the retard direction of the urging mechanism. Therefore, the driven-side rotator does not flutter and the idling operation is stabilized.

  On the other hand, when the rotational speed of the internal combustion engine is smaller than a predetermined rotational speed, for example, when the internal combustion engine stops, the pump stops and the fluid pressure disappears. It becomes larger than the urging force of the urging mechanism in the retard direction. As a result, the driven-side rotating body flutters in the retard direction and the advance direction until the camshaft completely stops. With this configuration, when the engine is stopped, the relative rotation phase can be displaced to a predetermined phase by using the flutter of the driven side rotating body. Therefore, the relative rotation phase can be restricted to a predetermined phase by the lock mechanism. Further, even when the internal combustion engine is abnormally stopped, the driven-side rotating body flutters due to cranking when the internal combustion engine is restarted, so that the relative rotational phase can be restricted to a predetermined phase by the lock mechanism. In this way, the relative rotational phase can be constrained to a predetermined phase based on the normal operation of the valve opening / closing timing control device by simply setting the strength of the urging force without performing special control, and restarting the internal combustion engine. It is possible to prepare for.

  The "displacement force consisting of the fluid pressure of the working fluid acting on the partition from the retarding chamber side" means "the fluid pressure of the working fluid acting on each partition from the retarding chamber" Means a displacement force having a magnitude obtained by multiplying the “distance between the center of action of the fluid pressure and the rotational axis” and the “number of partition portions”.

  A third characteristic configuration of the valve timing control device according to the present invention is that the strength of the urging force is determined based on torque fluctuation of the camshaft when the rotational speed of the internal combustion engine is a predetermined rotational speed. The displacement force acting on the body is set to be greater than the displacement force in the advance direction.

  For example, when the internal combustion engine is stopped, the internal combustion engine is not immediately stopped, the relative rotational phase is shifted to a predetermined phase, the control by the lock mechanism is confirmed, and the internal combustion engine is stopped. May be done. However, in the case of the apparatus of this configuration, in such a case, it is not necessary to shift the relative rotation phase to a predetermined phase by using the flutter of the driven side rotating body as described above. With this configuration, when the rotational speed of the internal combustion engine is equal to or lower than a predetermined rotational speed, for example, equal to or lower than the rotational speed during idling, the displacement in the advance direction of the displacement force based on the torque fluctuation of the camshaft The force is always countered by the biasing force of the biasing mechanism. Therefore, the driven-side rotator does not flutter and the idling operation is reliably stabilized. Also, with this configuration, it is easy to set the strength of the urging force of the urging mechanism.

It is a figure which shows the whole structure of the valve timing control apparatus which concerns on this invention. It is II-II sectional drawing of FIG. 1, Comprising: It is sectional drawing of the valve timing control apparatus at the time of a locked state. FIG. 3 is a cross-sectional view of the valve timing control device when the locked state of FIG. 2 is released. It is sectional drawing of the valve opening / closing timing control apparatus figure in case a relative rotational phase is a phase vicinity of the most retarded angle phase . It is sectional drawing of the valve opening / closing timing control apparatus figure in case a relative rotation phase is a phase of an advance side rather than a lock phase. It is sectional drawing of the valve timing control apparatus which concerns on another embodiment, Comprising: It is sectional drawing at the time of a locked state. It is sectional drawing of the valve opening / closing timing control apparatus which concerns on another embodiment, Comprising: It is sectional drawing when the locked state of FIG. 6 is cancelled | released. It is sectional drawing of the valve timing control apparatus which concerns on another embodiment, Comprising: It is sectional drawing when a relative rotational phase is a phase vicinity of the most retarded angle phase. It is sectional drawing of the valve opening / closing timing control apparatus which concerns on another embodiment, Comprising: It is sectional drawing when a relative rotational phase is a phase of an advance side rather than a lock phase.

  An embodiment in which the present invention is applied as a valve opening / closing timing control device on the intake valve side of an automobile engine will be described with reference to FIGS. That is, the automobile engine corresponds to the “internal combustion engine” of the present invention.

〔overall structure〕
As shown in FIG. 1, this valve opening / closing timing control device is arranged coaxially with respect to the housing 1 as a “drive side rotating body” that rotates synchronously with a crankshaft of an engine (not shown), An internal rotor 2 as a “driven rotor” that rotates in synchronization with the camshaft 101 is provided. The camshaft 101 is a rotating shaft of a cam (not shown) that controls opening and closing of the intake valve of the engine. The camshaft 101 is rotatably assembled to a cylinder head of an engine (not shown).

  Further, the valve opening / closing timing control device restricts the relative rotational movement of the inner rotor 2 with respect to the housing 1, thereby setting the relative rotational phase of the inner rotor 2 with respect to the housing 1 to a predetermined value between the most retarded angle phase and the most advanced angle phase. A lock mechanism 6 that can be restricted to the phase is provided.

[Internal rotor and housing]
As shown in FIG. 1, the internal rotor 2 is assembled integrally with the tip of the camshaft 101. On the inner diameter side of the inner rotor 2, a bottomed cylindrical concave portion opened to the camshaft 101 side is formed along the direction of the rotation axis X of the camshaft 101. The bottom surface of the recess is applied to the tip of the camshaft 101, and the inner rotor 2 is fastened and fixed to the camshaft 101 by bolts.

  The housing 1 includes a front plate 11 on the side opposite to the side to which the camshaft 101 is connected, an external rotor 12 integrally provided with a timing sprocket 15, a rear plate 13 on the side to which the camshaft 101 is connected, It has. The outer rotor 12 is externally mounted on the inner rotor 2 and is sandwiched between the front plate 11 and the rear plate 13. And the front plate 11, the external rotor 12, and the rear plate 13 are fastened with the volt | bolt.

  When the crankshaft is rotationally driven, the rotational driving force is transmitted to the timing sprocket 15 via the power transmission member 102, and the housing 1 is rotationally driven in the rotational direction S shown in FIG. As the housing 1 rotates, the internal rotor 2 rotates in the rotational direction S to rotate the camshaft 101, and the cam provided on the camshaft 101 pushes down the intake valve of the engine to open it.

  As shown in FIG. 2, the fluid pressure chamber 4 is formed by the outer rotor 12 and the inner rotor 2. The outer rotor 12 is formed with a plurality of projecting portions 14 projecting in the radially inward direction and spaced apart from each other along the rotational direction S. The protruding portion 14 functions as a shoe for the outer peripheral surface 2 a of the inner rotor 2. In the present embodiment, the fluid pressure chambers 4 are configured to be four places, but the present invention is not limited to this.

  A vane groove 21 is formed in a portion of the outer peripheral surface 2 a facing the fluid pressure chamber 4. In the vane groove 21, a vane 22 as a “partition portion” is disposed radially outward. The fluid pressure chamber 4 is partitioned by the vane 22 into an advance chamber 41 and a retard chamber 42 along the rotation direction S.

  As shown in FIGS. 1 and 2, an advance passage 43 is formed in the internal rotor 2 and the camshaft 101. The advance passage 43 communicates with each advance chamber 41. A retard passage 44 is formed in the internal rotor 2 and the camshaft 101. The retard passage 44 communicates with each retard chamber 42. As shown in FIG. 1, the advance passage 43 and the retard passage 44 are connected to a fluid supply / discharge mechanism 5 described later.

  The working fluid is supplied to, discharged from, or held by the fluid supply / discharge mechanism 5 with respect to the advance chamber 41 and the retard chamber 42, and the fluid pressure of the working fluid is applied to the vane 22. In this way, the relative rotational phase is displaced in the advance angle direction or the retard angle direction, or held at an arbitrary phase. That is, a displacement force of “fluid pressure × pressure receiving area of the vane 22 × distance between the pressure receiving surface center of the vane 22 and the rotational axis X × number of locations of the vane 22” acts on the inner rotor 2. This displacement force corresponds to the “displacement force comprising the fluid pressure of the working fluid acting on the partition portion from the retard chamber side” in the present invention. The advance angle direction is a direction in which the vane 22 rotates relative to the housing 1 and the volume of the advance chamber 41 increases, and is indicated by an arrow S1 in FIG. The retarding direction S2 is a direction in which the volume of the retarding chamber 42 increases, and is indicated by an arrow S2 in FIG.

  With such a configuration, the internal rotor 2 can smoothly rotate relative to the housing 1 around the rotation axis X within a certain range. A certain range in which the housing 1 and the inner rotor 2 can move relative to each other, that is, a phase difference between the most advanced angle phase and the most retarded angle phase corresponds to a range in which the vane 22 can be displaced inside the fluid pressure chamber 4. . It is to be noted that the retardation chamber 42 has the largest volume in the most retarded phase, and the advance chamber 41 has the largest volume in the most advanced phase.

  In the present embodiment, the most retarded angle phase is a phase where the valve closing timing of the exhaust valve and the valve opening timing of the intake valve are substantially the same, and even if the relative rotation phase is the most retarded angle phase, the engine Can be started.

[Lock mechanism]
The lock mechanism 6 keeps the housing 1 and the internal rotor 2 at a predetermined relative position in a situation where the fluid pressure of the working fluid is not stable immediately after the engine is started, so that the relative rotational phase becomes the most retarded angle phase and the most advanced phase. It is constrained to a predetermined phase between the angular phases (hereinafter referred to as “lock phase”). As a result, the rotational phase of the camshaft 101 with respect to the rotational phase of the crankshaft is properly maintained, and stable engine rotation appears. In the present embodiment, the lock phase is a phase in which valve opening timings of an unillustrated intake valve and exhaust valve partially overlap. As a result, hydrocarbons (HC) can be reduced when the engine is started, and a low emission engine can be obtained.

  As shown in FIGS. 1 and 2, the lock mechanism 6 includes a first lock portion 6A and a second lock portion 6B. The first lock portion 6 </ b> A includes a lock passage 61, a lock groove 62, an accommodation portion 63, a plate-like lock member 64, a spring 65, and a ratchet portion 67.

  The lock passage 61 is formed in the internal rotor 2 and the camshaft 101 and connects the lock groove 62 and a predetermined port of a fluid switching valve 54 described later. By controlling the fluid switching valve 54, the working fluid can be supplied to and discharged from the lock groove 62 via the lock passage 61. The lock groove 62 is formed on the outer peripheral surface 2 a of the inner rotor 2. A ratchet 67 having a shallower radial depth than the lock groove 62 is formed adjacent to the advance side of the lock groove 62. The accommodating part 63 is formed in the external rotor 12. The lock member 64 is disposed in the housing portion 63 and can be moved in and out in the radial direction along the shape of the housing portion 63. The spring 65 is disposed in the housing portion 63 and biases the lock member 64 radially inward, that is, toward the lock groove 62.

  When the working fluid is discharged from the lock groove when the relative rotational phase is displaced from the phase on the advance side of the lock phase to the lock phase, the lock member 64 is directly engaged with the lock groove 62. When the lock member 64 is engaged with the lock groove 62, the relative rotation phase is restricted to a predetermined range from the lock phase to the phase on the advance side with respect to the lock phase. This range can be adjusted by the circumferential groove width of the lock groove 62. When the fluid switching valve 54 is controlled to supply the working fluid to the lock groove 62, the lock member 64 is retracted from the lock groove 62 toward the accommodating portion 63, and the restriction on the relative rotation phase is released.

  When the working fluid is discharged from the lock groove when the relative rotational phase is shifted from the phase retarded from the lock phase to the lock phase, the lock member 64 is first engaged with the ratchet portion 67 and then the lock groove. Engage with 62. As long as the internal rotor 2 performs relative rotation, the time during which the lock member 64 faces the lock groove 62 is short, and the lock member 64 cannot be reliably engaged with the lock groove 62. As described above, when the ratchet portion 67 is provided, the relative rotational phase can be converged to the predetermined phase while being regulated in a predetermined range stepwise. For this reason, the certainty that the lock member 64 engages with the lock groove 62 is improved.

  Usually, immediately before the engine stop operation is performed, the engine performs an idling operation, and the relative rotation phase during the idling operation is often near the most retarded angle phase. That is, immediately before the lock mechanism 6 needs to operate so as to constrain the relative rotation phase to the lock phase, the relative rotation phase is often on the retarded side of the lock phase. Therefore, the ratchet portion 67 is formed on the advance side with respect to the lock groove 62.

  The second lock portion 6 </ b> B includes a lock passage 61, a lock groove 62, an accommodation portion 63, a lock member 64, a spring 65, and a ratchet portion 67. Since the second lock portion 6B has substantially the same configuration as the first lock portion 6A, description of the same configuration will be omitted. When the lock member 64 is engaged with the lock groove 62, the relative rotation phase is restricted to a predetermined range from the lock phase to the phase on the retard side from the lock phase. The lock groove 62 of the first lock portion 6A and the lock groove 62 of the second lock portion 6B communicate with each other via the communication groove 66 and the ratchet portion 67 of the second lock portion 6B. When the fluid switching valve 54 is controlled to supply the working fluid to the lock groove 62 of the first lock portion 6A, the working fluid is also supplied to the lock groove 62 of the second lock portion 6B, and the lock member 64 is moved from the lock groove 62. Retraction to the housing 63 side releases the restriction on the relative rotational phase.

  Since the first lock portion 6A and the second lock portion 6B are thus configured, as shown in FIG. 2, both the lock member 64 of the first lock portion 6A and the lock member 64 of the second lock portion 6B are Simultaneously engaging the lock groove 62 of the first lock portion 6A and the lock groove 62 of the second lock portion 6B respectively restricts the relative rotational movement of the rotors 1 and 2 and restricts the relative rotational phase to the lock phase. Can do.

  Further, for example, the timing at which the lock member 64 is engaged with the ratchet portion 67 in the first lock portion 6A and the timing at which the lock member 64 is engaged with the ratchet portion 67 in the second lock portion 6B are made different. By forming both the lock grooves 62, the number of stages of stepwise regulation of the relative rotation phase is increased, and the operational reliability of the lock mechanism 6 can be improved.

  As the shape of the lock member 64, a pin shape or the like can be appropriately employed in addition to the plate shape shown in the present embodiment.

[Fluid supply / discharge mechanism]
The configuration of the fluid supply / discharge mechanism 5 will be briefly described. As shown in FIG. 1, the fluid supply / discharge mechanism 5 includes an oil pan 51 that stores engine oil that is an example of “working fluid”, an oil pump 52 that is driven by the engine to supply engine oil, and an advance passage. 43 and an electromagnetic control type fluid control valve (OCV) 53 for controlling supply, discharge and retention of engine oil to the retard passage 44 and an electromagnetic control type fluid for controlling supply and discharge of engine oil to the lock passage 61. And a switching valve (OSV) 54. The fluid control valve 53 and the fluid switching valve 54 are controlled by the ECU 7.

  The oil pump 52 is a mechanical hydraulic pump that is driven by transmission of the rotational driving force of the crankshaft. The oil pump 52 sucks the engine oil stored in the oil pan 51 and discharges the engine oil downstream.

  The fluid control valve 53 is configured as a spool type, and operates based on control of the amount of power supplied by the ECU 7 (engine control unit). By switching the fluid control valve 53, hydraulic oil is supplied to the advance chamber 41, hydraulic oil is discharged from the retard chamber 42, hydraulic oil is discharged from the advance chamber 41, hydraulic oil is supplied to the retard chamber 42, and advanced. It is possible to perform control such as supply / discharge of hydraulic oil to / from the chamber 41 and the retard chamber 42. Control for supplying hydraulic oil to the advance chamber 41 and discharging hydraulic oil from the retard chamber 42 is “advance control”. When the advance angle control is performed, the vane 22 moves relative to the external rotor 12 in the advance direction S1, and the relative rotation phase is displaced toward the advance side. Control for discharging hydraulic oil from the advance chamber 41 and supplying hydraulic oil to the retard chamber 42 is “retard control”. When the retard control is performed, the vane 22 relatively rotates in the retard direction S2 with respect to the external rotor 12, and the relative rotation phase is displaced to the retard side. If control is performed to shut off the supply and discharge of hydraulic oil to and from the advance chamber 41 and the retard chamber 42, the vane 22 does not move relative to each other, and the relative rotation phase can be maintained at an arbitrary phase.

  The fluid control valve 53 sets the opening degree by adjusting the duty ratio of the electric power supplied to the electromagnetic solenoid. Thereby, fine adjustment of the supply and discharge amount of engine oil is possible.

  The fluid switching valve 54 is configured as a spool type and operates based on control of the amount of power supplied by the ECU 7 (engine control unit). By switching the fluid control valve 53, control such as supply of engine oil to the lock groove 62 and discharge of engine oil from the lock groove 62 is possible.

[Torsion spring]
As shown in FIG. 1, a torsion spring 3 is provided across the inner rotor 2 and the front plate 11. The torsion spring 3 acts on the housing 1 and the inner rotor 2 so that the relative rotational phase becomes the most retarded phase. The torsion spring 3 corresponds to the “biasing mechanism” in the present invention.

  The strength of the urging force of the torsion spring 3 is determined by the sum of the urging force and the displacement force composed of the engine oil pressure acting on the vane 22 from the retard chamber 42 side when the engine is idling. It is set to be larger than the displacement force in the advance direction among the displacement forces acting on the internal rotor 2 based on the torque fluctuation of the camshaft 101 during the idling operation. The strength of the urging force of the torsion spring 3 is equal to or less than the displacement force in the advance direction of the displacement force acting on the internal rotor 2 based on the torque fluctuation of the camshaft 101 when the engine is idling. It is set to become. The strength of the urging force is finely adjusted by changing the effective diameter and the number of turns of the torsion spring 3.

  With this configuration, the internal rotor 2 has an urging force by the urging mechanism and an average displacement force in the retarding direction based on the torque fluctuation of the camshaft 101 as the force for relative rotational movement in the retarding direction. It always works. Therefore, even when the internal combustion engine is appropriately started with the relative rotational phase being constrained to the predetermined phase by the lock mechanism 6, the idling operation is performed, and the urging force of the torsion spring 3 is reduced even if the engine oil pressure received by the vane 22 decreases. And the average displacement force in the retard direction based on the torque fluctuation of the camshaft 101, the relative rotational phase can be stabilized to the most retarded phase or a phase near the most retarded phase. As a result, even if the capacity of the oil pump 52 is reduced, the idling operation can be stabilized.

  Furthermore, with this configuration, the displacement force in the advance direction out of the displacement force based on the torque fluctuation of the camshaft 101 is canceled out by the urging force of the torsion spring 3. Therefore, the internal rotor 2 does not flutter and the idling operation becomes more stable.

[Other configurations]
Although not shown, a crank angle sensor that detects the rotation angle of the crankshaft of the engine and a camshaft angle sensor that detects the rotation angle of the camshaft 101 are provided. The ECU 7 detects the relative rotation phase from the detection results of the crank angle sensor and the camshaft angle sensor, and determines whether the relative rotation phase is on the advance side or the retard side with respect to the lock phase. judge.

  Although not shown, the ECU 7 is formed with a signal system for acquiring ignition key ON / OFF information, information from an oil temperature sensor for detecting the oil temperature of the engine oil, and the like. Further, in the memory of the ECU 7, control information on the optimum relative rotational phase corresponding to the operating state of the engine is stored. The ECU 7 controls the relative rotation phase from the information on the operation state (engine rotation speed, cooling water temperature, etc.) and the control information described above.

[Operation of valve timing control device]
As described above, the present valve opening / closing timing control device starts the engine in a state where the relative rotation phase is constrained to the lock phase by the lock mechanism 6 as shown in FIG. When the engine is properly started, the fluid control valve 53 is controlled, and engine oil is supplied to the lock groove 62 to retract the lock member 64 from the lock groove 62. As shown in FIG. Release the phase constraint.

  Thereafter, as shown in FIG. 4, the relative rotational phase is displaced to a phase near the most retarded phase suitable for idling operation. At this time, since the inner rotor 2 is biased in the slowest direction by the biasing force of the torsion spring 3, the inner rotor 2 does not flutter, the relative rotational phase is stabilized, and a stable idling operation is executed. The

  Thereafter, in a normal operation state, the relative rotational phase is displaced to a phase retarded from the lock phase as shown in FIG. 4 according to the engine load, rotational speed, etc., or as shown in FIG. The rotational phase is displaced to a phase on the more advanced side than the lock phase.

  When the ignition key is turned OFF and the engine is stopped, the oil pump 52 is also stopped, and the supply and discharge of engine oil to the retard chamber 42 and the advance chamber 41 are also stopped. As a result, the engine oil pressure acting on the vane 22 also decreases. On the other hand, even if the engine stops, it takes time until the camshaft 101 completely stops. Therefore, a displacement force based on the torque fluctuation of the camshaft 101 acts on the internal rotor 2. At this time, of the displacement force based on the torque fluctuation of the camshaft 101, the displacement force in the advance direction is larger than the urging force in the retard direction of the lotion spring 3. Fluttering. Due to this fluttering, the relative rotational phase is displaced near the lock phase. As a result, the relative rotation phase is constrained to the lock phase by the lock mechanism 6. In this way, the relative rotation phase can be constrained to the lock phase based on the normal operation of the valve timing control device.

  Further, for example, when the outside air temperature is low, the engine may be stalled on the low-speed rotation side where the operating state of the engine is unstable. In this case, it is necessary to shift the relative rotation phase to the lock phase in order to restart the engine. On the other hand, when the engine is rotating at a low speed, the relative rotation phase is often near the most retarded angle phase. When the engine is restarted, the camshaft 101 is rotated by cranking, and a displacement force based on torque fluctuation of the camshaft 101 at that time acts on the internal rotor 2. Therefore, the inner rotor 2 flutters. As a result, the lock member 64 engages with the ratchet portion 67 and further engages with the lock groove 62.

  Even if the relative rotation phase is not constrained by the lock phase when the engine is stopped and restarted after the engine stall, as described above, the engine according to this embodiment has the relative rotation phase at the most retarded phase. There is no big problem because it can be started.

[Another embodiment]
Another embodiment of the valve timing control apparatus according to the present invention will be described with reference to FIGS. FIG. 6 is a cross-sectional view corresponding to FIG. 2 according to the above-described embodiment, and is a cross-sectional view of the valve opening / closing timing control device in the locked state. 7 to 9 are cross-sectional views of the valve timing control apparatus during idling and normal operation. FIG. 7 is a cross-sectional view when the lock by the lock mechanism 6 is released. FIG. 8 is a cross-sectional view when the relative rotational phase is in the vicinity of the most retarded phase. FIG. 9 is a cross-sectional view when the relative rotation phase is a phase on the advance side with respect to the lock phase. A description of the same configuration as that of the above-described embodiment is omitted. In addition, the same reference numerals are assigned to the same components. The set value of the strength of the urging force of the torsion spring and the configuration of the lock mechanism 6 are different from the above-described embodiment.

[Lock mechanism]
As shown in FIGS. 1 and 6, the lock mechanism 6 includes a first lock portion 6A and a second lock portion 6B. The first lock portion 6 </ b> A and the second lock portion 6 </ b> B include a lock passage 61, a lock groove 62, a storage portion 63, a plate-like lock member 64, and a spring 65. The lock groove 62 is a groove common to the first lock portion 6A and the second lock portion 6B.

  The lock passage 61 connects the lock groove 62 and a predetermined port of the fluid switching valve 54. By controlling the fluid switching valve 54, the working fluid can be supplied to and discharged from the lock groove 62 via the lock passage 61.

  When the working fluid is discharged from the lock groove when the relative rotation phase is displaced from the phase on the advance side of the lock phase to the lock phase, both lock members 64 of the first lock portion 6A and the second lock portion 6B are Engage with the lock groove 62. When both lock members 64 are engaged with the lock groove 62, the relative rotational movement of the inner rotor 2 stops, and the relative rotational phase is constrained by the lock phase. When the fluid switching valve 54 is controlled to supply the working fluid to the lock groove 62, both lock members 64 are retracted from the lock groove 62 toward the accommodating portion 63, and the restriction on the relative rotational phase is released.

[Torsion spring]
The strength of the urging force of the torsion spring 3 is not less than the displacement force in the advance direction of the displacement force acting on the internal rotor 2 based on the torque fluctuation of the camshaft 101 when the engine is idling. It is set.

  With this configuration, the internal rotor 2 has an urging force by the urging mechanism and an average displacement force in the retarding direction based on the torque fluctuation of the camshaft 101 as the force for relative rotational movement in the retarding direction. It always works. Therefore, after the internal combustion engine is appropriately started with the relative rotational phase restricted to the predetermined phase by the lock mechanism 6, the idling force and the urging force of the torsion spring 3 are reduced even if the engine oil pressure received by the vane 22 decreases. The relative rotational phase can be stabilized at the most retarded phase or a phase near the most retarded phase by the average displacement force in the retarded direction based on the torque fluctuation of the camshaft 101 described above. As a result, even if the capacity of the oil pump 52 is reduced, the idling operation can be stabilized.

  Further, with this configuration, the displacement force in the advance direction among the displacement forces based on the torque fluctuation of the camshaft 101 is always canceled out by the urging force of the torsion spring 3. Therefore, the internal rotor 2 does not flutter and the idling operation is reliably stabilized.

[Operation of valve timing control device]
Since the operation at the time of engine start and normal operation is the same as that of the above-described embodiment, it will not be described here. In this embodiment, delay control is performed when the engine is stopped. Specifically, when the ignition key is turned off, the ECU 7 issues a command to supply engine oil to the advance chamber 41. When the ECU 7 determines that the relative rotational phase is constrained to the lock phase as shown in FIG. 6, the ECU 7 instructs the engine to stop. When restarting after an abnormal engine stop such as an engine stall, the ECU 7 controls the relative rotation phase to be the lock phase when determining that the relative rotation phase is not constrained by the lock phase. Thus, since the relative rotational phase is reliably restrained to the lock phase by the lock mechanism 6, the engine is started at a suitable phase, resulting in low emissions.

  The present invention can be used for a valve opening / closing timing control device of an automobile or other internal combustion engine.

1 Housing (drive side rotating member)
2 Internal rotor (driven side rotating member)
3 Torsion spring (biasing mechanism)
4 Fluid pressure chamber 5 Fluid supply / discharge mechanism 6 Lock mechanism 22 Vane (partition)
41 Advance chamber 42 Delay chamber 101 Camshaft

Claims (1)

A drive side rotating body that rotates synchronously with the crankshaft of the internal combustion engine;
A driven-side rotating body that is coaxially disposed with respect to the driving-side rotating body and that rotates synchronously with a camshaft for opening and closing the valve of the internal combustion engine;
A fluid pressure chamber formed by the driving side rotating body and the driven side rotating body;
A partition provided on at least one of the driving side rotating body and the driven side rotating body to partition the fluid pressure chamber into a retarding chamber and an advance chamber;
A fluid supply / discharge mechanism capable of controlling supply / discharge of the working fluid to / from the fluid pressure chamber;
A lock mechanism capable of constraining the relative rotational phase of the driven-side rotator with respect to the driving-side rotator to a predetermined phase between a most retarded angle phase and a most advanced angle phase;
An urging mechanism that constantly applies an urging force to the drive-side rotator and the driven-side rotator so as to displace the relative rotation phase toward the most retarded angle phase ;
The strength of the urging force is determined by a displacement force composed of a fluid pressure of the working fluid acting on the partition portion from the retard chamber side when the rotational speed of the internal combustion engine is a predetermined rotational speed, and the urging force. Is greater than the displacement force in the advance direction of the displacement force acting on the driven-side rotating body based on the torque fluctuation of the camshaft when the rotation speed of the internal combustion engine is the predetermined rotation speed. And the biasing force is a displacement in the advance direction of the displacement force acting on the driven rotating body based on the torque fluctuation of the camshaft when the rotational speed of the internal combustion engine is the predetermined rotational speed. Valve opening / closing timing control device set so as to be less than force.

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